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At least 361 records · Page 20Linked to original sources
PubMed1981

Uterine blood flow and timing of blastocyst implantation in the guinea pig.

The temporal and direct relationships between serum estradiol (E) and progesterone (P) levels and uterine blood flow (UBF) and intrauterine oxygen tension (IU PO2) were examined in guinea pigs between days 1 and 8 of pregnancy. Both UBF and IU PO2 were measured in situ using a noninvasive electromagnetic blood flow monitor and needle oxygen electrode, respectively. Serum P levels remained relatively constant throughout the first 8 days of pregnancy. In contrast, serum E levels declined to basal levels between days 1 and 3, and then subsequently rose between days 4 and 7 before again falling to basal levels by day 8. The changes in UBF and IU PO2 paralleled those of serum E levels, both exhibiting a rise between days 5 and 6. The direct effect of oil, E, or P injections on UBF and IU PO2 measurements in ovariectomized animals indicated that E induced a dramatic rise in both uterine parameters, whereas both measurements remained at basal levels after oil or P treatment. The results of this study indicate that UBF and IU PO2 levels are directly regulated by the cyclic fluctuations in serum E. The temporal relationship between the days 4 to 7 rise in serum E, UBF, and IU PO2 levels and the timing of blastocyst implantation suggest that these events are involved in uterine preparation for nidation in the guinea pig.

Animals↗
PubMed1997

Estrogen-regulated uterine vascularization modulates the guinea pig intrauterine environment.

The effects of experimentally-induced, uterine vascular restriction on uterine blood flow (UBF) and uterine blood volume (UBV) capacity, as well as the dependent intrauterine oxygen tension (IUpO2) measurements used as an indication of luminal nutrient availability, were examined using ovariectomized, estrogen (E)-treated guinea pigs. Following 3 days of E treatment, both UBF and UBV measurements were found to be elevated and associated with a causally-related increase in intraluminal uterine oxygen availability levels. Following the acute clamping of the uterine arteries, both UBF and UBV levels decreased dramatically and induced a rapid fall in associated intrauterine luminal oxygen tension measurements. As a result of chronic (i.e., 6 h) restriction of segmental blood flow to the uterus by vascular cauterization, both UBV and IUPO2 levels were suppressed as compared with sham-operated control levels, whereas UBF rates were not significantly altered. The results of the present studies are the first quantitative demonstration that either acute or chronic reductions in uterine vascular capacity or competency can induce rapid and dramatic changes in the intrauterine nutritional environment recognized to be essential for the initiation, support and maintenance of nidation and subsequent fetal-placental development.

Animals↗
PubMed1996

Use of fibrin sealant for reproductive surgery: a randomized study in the rabbit model.

The present study was undertaken to compare adhesion formation and reproductive outcome after reproductive surgery with or without the application of fibrin sealant. At laparotomy, the ovaries and uterine horns of 20 rabbits were longitudinally incised on the antimesenteric side using a monopolar microneedle. At random, one ovary and the ipsilateral uterine horn were covered with fibrin sealant, while those on the contralateral side were left uncovered without application of sutures. The rabbits were then mated, and 2 weeks later a second-look laparotomy was performed by a blinded observer. No statistically significant differences were found in postoperative adhesions, number of corpora lutea in each ovary, number of embryos in the ipsilateral uterine horn, and nidation index for each side. Fibrin sealant for conservative surgery does not appear to significantly affect either postoperative adhesion formation or reproductive outcome.

Animals↗
PubMed1986

Absorbable or nonabsorbable suture material for microsurgical tubal anastomosis. Randomized experimental study on rabbits.

In 20 female rabbits the influence of absorbable and nonabsorbable suture material on microsurgical anastomosis of the oviduct was investigated. No significant superiority of polyglactin 910 over polypropylene could be demonstrated. Concerning histological reaction to the different suture materials as well as pregnancies (calculated by nidation indices) the results were comparable. The modern suture materials obviously do not influence the functional sequelae of microsurgical reanastomosis of the rabbit fallopian tube.

Animals↗
PubMed1984

Delayed endometrial maturation in women with normal progesterone levels. The dysharmonic luteal phase syndrome.

In 121 women attending the infertility clinic between 1978 and 1982, 127 cycles with luteal phases of 10 days or more were investigated by a complete basal body temperature (BBT) chart, three plasma progesterone assays taken between 11 and 4 days before menses, and a dated endometrial biopsy (EB) taken at the time of the last blood sample. All parameters were normal in 78 women (64.4%) categorized as group I 'normal luteal phases (NLP)'. There were some discordances between the three parameters in the remaining 43 women: 8 had normal BBT but low progesterone levels and delayed EB. They form group II 'inadequate luteal phases'. 29 women (23.9%) had delayed EB despite normal progesterone levels: forming group III 'dysharmonic luteal phases (DLP)'. 6 women had advanced EB and normal progesterone levels: group IV. Apart from endometrial maturation, there was no difference between NLP and DLP, neither in clinical parameters (length of the follicular phase, date and duration of the thermal shift, length of the luteal phase), nor in progesterone levels. Fertilization occurred in four DLP biopsied cycles: pregnancies went normally to term, giving birth to normal babies. Therefore, the DLP syndrome, characterized by normal midluteal progesterone levels and a delayed endometrial development, is not incompatible with normal nidation and gestation.

Adult↗
PubMedDate not supplied

Investigation of ovum transport in the oviduct: the dynamics of oviductal fluids in domestic rabbits.

Ova are captured by the oviductal fimbria and rapidly transported to the ampullary-isthmic junction of the fallopian tube. Fertilized ova and oviductal fluids are then carried medially in the fallopian tube, while undergoing maturation in preparation for entering the uterine cavity, where nidation and further development take place. This movement of oviductal fluids was visualized in a rabbit model with human chorionic gonadotropin-induced ovulation, by injection of a contrast medium into the ampulla region of the oviduct. In the ampulla, the opaque medium was observed to oscillate at 0-85.4 mm/s. This medial transport of the fluid towards the uterus decreased to 0-9.6 mm/s in the isthmic portion of the tube. This decrease substantiates previous findings that the transport of material in the isthmic portion of the oviduct is more strongly under the control of ciliary action than under peristaltic activity.

Animals↗
PubMed1976

Termination of pregnancy by sheep anti-LHRH gamma globulin in rats.

The effect of the administration of sheep anti-LHRH gamma-globulin (anti-LHRHG) on the maintenance of pregnancy was investigated in rats. Nidation was confirmed by laparotomy on day 7 or 8 of pregnancy. In one experiment, rats were then injected iv with 1 ml anti-LHRHG or normal sheep gamma-globulin (NSG) daily from days 7 to 11. The uteri were inspected again on day 14 of pregnancy, when it was found that complete resorption of the fetuses had occurred in the anti-LHRHG-treated rats, but that the fetuses were normal in the NSG-treated control rats. The effect of a single injection of 1 ml of anti-LHRHG on day 7, 8, 9, 10, 11, or 12 of pregnancy was also investigated. Administration on day 9 or 10 resulted in complete resorption of the fetuses by the time of the 2nd inspection on day 14, and treatment on day 8 or 11 was partially effective. However, treatment on day 7 or 12 exerted little effect on viability of the fetuses. None of the rats showed vaginal bleeding following treatment with anti-LHRHG. Termination of pregnancy by anti-LHRHG could be prevented by SC injection of 1 mug LHRH twice daily, or by 4 progesterone SC once daily, from days 9 through 12 of pregnancy. The ovaries of the rats treated with anti-LHRHG from days 7 to 11 were smaller than those of the NSG-treated control rats, and some of the corpora lutea underwent cystic degenerative changes. Lutein cells of the former were also smaller than those of the latter. Serum progesterone levels were reduced after a single injection of anti-LHRHG on day 9 or 10, but not on day 7 or 12 of pregnancy. There was excellent agreement between the reduction of serum progesterone and fetal resorption. Serum LH levels were low on days 7 through 12 in the anti-LHRHG-treated as well as the NSG-treated rats, and the possible suppressive effect of anti-LHRHG on LH could not be revealed because of insufficient sensitivity of the radioimmunoassay method. No significant difference was observed in serum prolactin levels between the groups of rats. The results clearly indicate that LHRH, by maintaining progesterone secretion, is indispensable on days 9 and 10 of pregnancy for the maintenance of pregnancy.

Abortion, Induced↗
PubMed1976

Endometrial content of nuclear estrogen receptor and receptivity for ovoimplantation in the rat.

The purpose of this study was to provide information concerning the amount of nuclear binding sites for estrogen in endometrial cells during the first week of pregnancy in the rat. The "insoluble" (high-salt non-extractable) binding during the first four days of pregnancy follows a circadian rhythm, with a maximal value at midnight, and a minimal one a noon. By day 5, the amount plateaus at a minimal value. The number of estradiol binding sites of the soluble (high-salt extractable) nuclear fraction shows a similar pattern. All the necessary elements for the estrogen-dependent induction of endometrial receptivity for nidation appear, therefore, to be present already by day 3, but the turning on of the endometrial response to estrogen on day 4 seems to depend on additional factor(s).

Animals↗
PubMed2006

Down-regulation of endometrial matrix metalloproteinase-3 and -7 expression in vitro and therapeutic regression of experimental endometriosis in vivo by a novel nonsteroidal progesterone receptor agonist, tanaproget.

CONTEXT: Endometriosis, the growth of endometrial tissue outside the uterus, is principally an estrogen-dependent disease. In contrast, exposure to progesterone during pregnancy or therapeutically has been shown to provide benefit to some women with this disease. However, recent research suggests that the presence of endometriosis impairs the capacity of the eutopic endometrium to respond to endogenous progesterone. OBJECTIVE: Reduced progesterone responsiveness results in an elevated endometrial expression of matrix metalloproteinases (MMPs) during the secretory phase of the menstrual cycle in women with endometriosis. Although cyclic MMP expression is critical for endometrial growth and remodeling, the failure of progesterone to down-regulate MMPs may impair nidation and promote the invasive establishment of endometriosis. In the current study we examined the ability of a newly developed progesterone receptor (PR) agonist, tanaproget (TNPR), to down-regulate endometrial MMP expression in vitro and regress experimental endometriosis in vivo. SETTING: This study was performed at a university-based medical center. PARTICIPANTS: Asymptomatic volunteers and patients with endometriosis were studied. MAIN OUTCOME MEASURES: We examined the ability of TNPR to down-regulate endometrial MMP expression in vitro compared with that of natural progesterone and two currently marketed synthetic steroidal progestins. Using a human/mouse model of endometriosis, we also tested the in vivo ability of TNPR to regress ectopic lesions established by tissues with reduced progesterone sensitivity. RESULTS: TNPR effectively down-regulated MMP expression in vitro and induced significant reduction of lesions in mice with disease established by tissues from endometriosis patients. CONCLUSION: Given the positive preclinical pharmacological profile of TNPR that has recently been reported, additional development of this compound for the treatment of endometriosis is warranted.

Adolescent↗
PubMed1984

Effects of intrauterine instillation of antiserum to hCG during early pregnancy in mice.

Human chorionic gonadotrophin (hCG)-like activity has been reported in mouse and rabbit blastocysts. The presence of this hCG-like activity seems to be essential for nidation of the pre-implantation embryo. Binding sites for hCG were localised on day 4 mouse embryos by immunohistochemical techniques. Presence of hCG-like activity was confirmed by cytotoxicity test. The number of implantation sites was significantly reduced on day 8 of pregnancy. Prior treatment to day 4 mouse embryos with hCG antiserum, for 1 h in utero or in vitro and their subsequent transfer to uteri of synchronised pseudopregnant mice resulted in impaired implantation of embryos, compared to controls treated with normal rabbit serum (NRS). These results suggest that hCG-like activity present on the pre-implantation embryo may have a significant role in implantation of the embryo.

Animals↗
PubMed1975

The function of the growing follicle.

The follicle plays a major role in the dual function of the ovary--oocyte maturation and release and steroidogenesis required for regulating its own growth and providing the proper environment in reproductive organs for the transport of gametes and nidation. Some aspects of how follicles attain their functional competence following a series of developmental changes are discussed. The presentation is based on data obtained mainly in rodents in which follicular development occurs postnatally. The peak activity of follicular growth occurs during the 1st week of life, but not until the 5th day is follicular development clearly dependent upon gonadotrophin stimulation. The formation of the theca layer and zona pellucida, differentiation of the vascular system and competence to respond to gonadotrophins are acquired during the 2nd week. FSH alone is primarily responsible for granulosa cell proliferation and the integrity of the granulosa cell membrane, but has little differential effect on steroidogenic enzymes. Synergism of FSH and LH promotes an enrichment of the theca layer, enhancement of vascular development and antrum formation, and induces a marked differential stimulation of 20alpha-hydroxysteroid dehydrogenase, aromatizing and cholesterol side-chain cleavage systems. The number of gonadotrophin receptors on granulosa and theca cells increases with follicular development. Steroids secreted by the ovary seem to modulate follicular growth, not only by effects upon FSH and LH release but also by a local influence within the ovary. A number of physiological events related to follicular function are explained according to these observations.

Age Factors↗
PubMed1998

Transforming growth factor beta and the endometrium.

During the oestrous or menstrual cycle and throughout much of pregnancy, the uterine endometrium undergoes rapid, as well as progressive, morphological and functional modification. During the preimplantation stage of pregnancy, the endometrium provides an environment that sustains embryonic development, and then participates in the nidation process. Later, the endometrium contributes the maternal component of the fetomaternal placenta. For a successful pregnancy, the placenta must orchestrate and regulate opposing forces. Trophoblast invasion must be limited to protect the uterus from destruction, while the allogenic fetus must be guarded from maternal immunological attack. Because of their powerful effects on the cellular and molecular processes associated with cellular proliferation and differentiation, angiogenesis and immunomodulation, the transforming growth factor beta (TGF-beta) polypeptides have been identified as potential modulators of many endometrial functions. Here, we examine the literature concerning cell-specific and temporal patterns of TGF-beta expression in the uterine endometrium during the oestrous cycle and pregnancy and evaluate the influence of ovarian steroids on TGF-beta expression in a range of species. Studies of the function of TGF-beta in the endometrium and at the fetomaternal interface are reviewed and discussed.

Endometrium↗
PubMed1977

Advances in tuboplasty.

Reconstructive oviductal surgery was performed on 205 private patients with primary and secondary infertility, who were selected from 1075 endoscopic examinations. Each patient underwent an infertility survey which included gamete formation, reception and deposition of gametes, nidation, post-coital, and semen analysis. Only those with tubal abnormalities, not responding to conservative therapy after a minimum period of six months following laparoscopic examination, were selected for tuboplasty. Spiral stents for fimbrioplasty and straight teflon tubing for mid-portion and cornua obstruction were employed. These stents were removed eight weeks post-surgery, under local anesthesia at the office. Of the 205 tuboplasties, 193 patients had sustained patency; 75 conceived; 7 aborted; and 1 had an ectopic pregnancy. Pregnancy occurred between 1 and 26 months after removal of the stents. Complications were very few. The use of Roland spiral teflon stents has resulted in a greater percentage in patency and pregnancy rates, as compared to those without use of stents.

Fallopian Tubes↗
PubMed1993

Demonstration of Fc gamma receptors in human endometrium.

Cryostat sections of human endometrium bound sheep erythrocytes (E) sensitized with rabbit IgG antibody (A), (EA). Unsensitized E were not bound. Native, heat-aggregated IgG and Fc fragments of IgG inhibited the binding of EA, whereas IgM, IgA and F(ab')2 fragments of IgG did not. The data indicate the presence of receptors for the Fc part of IgG (FcR). Using immune complexes of horseradish peroxidase (HRP) and rabbit IgG antibodies to HRP and monoclonal antibodies (mAbs), FcR were located to the glandular epithelial and endothelial cells, macrophages and predecidual cells of the stroma. These structures were also stained by mAbs against all three FcR classes and a 40-kD low affinity placental FcR. Preliminary results indicate that the expression of FcR varies during different stages of the menstrual cycle. FcR in the endometrium may play a rôle in local immunoregulation necessary for nidation and development of the blastocyst.

Adult↗
PubMed1977

Prevention of implantation by [D-Trp6-LH-RH in the rat: comparative study with the effects of large doses of HCG on pregnancy.

Effect of large doses of [D-Trp6]-LH-RH and HCG on implantation of fertilized ova was examined in the rat. Subcutaneous administration of 6ug[D-Trp6]-LH-RH per day from days 1 to 5 of pregnancy by an implanted minipump completely prevented the implantation of fertilized ova associated with a dramatic reduction of plasma progesterone on days 4 and 8, with a slight reduction of estradiol on day 4. There was no balooning of the uterus in the exploratory laparatomy on days 8 and 14. Administration of 1000 U of HCG daily from days 1 to 5 partially prevented implantation and completely terminated gestation. However, plasma progesterone and estradiol levels did not differ from those in the control animals. Ovaries in the [D-Trp6]-LH-RH treated rats appeared to be the same in size as those of the control pregnant rats, whereas the ovaries of the HCG-treated rats were hypertrophied. The results suggest that [D-Trp6]-LH-RH prevents nidation through a mechanism different from that for the adverse effect of excess of HCG on pregnancy.

Animals↗
PubMed1996

Alteration of E-cadherin, alpha- and beta-catenin mRNA expression in human uterine endometrium during the menstrual cycle.

To study the biological functions of the adherens junction in uterine endometrium at the reproductive phase, we measured the levels of E-cadherin, alpha- and beta-catenin mRNA in endometrium with or without an intramuscular injection of estradiol dipropionate in patients 5 days before hysterectomy. The levels of E-cadherin, alpha- and beta-catenin mRNA in endometria of the proliferative phase were significantly less than those of the secretory phase. The treatment with estradiol dipropionate significantly reduced the levels of alpha- and beta-catenin mRNA in endometria of the secretory phase, and tended to reduce that of E-cadherin mRNA. In conclusion, the functions of the adherens junction, which regulates the adhesive capacity of endometrial epithelial cells, are considered to be activated after ovulation, and at least in part associated with nidation.

Adult↗
PubMedDate not supplied

Pathologic examination of placentas from singleton and twin pregnancies obtained after in vitro fertilization and embryo transfer.

A pathologic investigation was conducted on 100 placentas collected from pregnancies resulting from in vitro fertilization (IVF) and intrauterine embryo transfer (ET), including 70 singleton pregnancies, 20 twin pregnancies, and 10 multiple pregnancies complicated by the vanishing twin (VT) phenomenon (n = 5) or artificially reduced (n = 5). These results were compared with those for 70 spontaneous spontaneous singleton and 20 spontaneous twin pregnancies. In cases of singleton pregnancies, the incidence of abnormal placental shapes was significantly different (P < .025) in the IVF group compared to controls. A significant (P < .005) difference was also observed between these groups in terms of umbilical cord insertion. The mean distance between the cord insertion and the closest placental margin was significantly (P < .001) shorter among IVF singleton pregnancies (3.19 +/- 1.83 versus 4.62 +/- 2.23 cm). In cases of twin pregnancy, no difference was found between IVF and spontaneous pregnancy in the incidence of pregnancy complications and distribution of cord insertion. First-trimester bleeding was the only clinical sign of the disappearance of an embryo in multiple pregnancies complicated by the VT phenomenon and was not observed in multiple pregnancies artificially reduced. The present findings support the hypothesis that marginal cord insertion is secondary to oblique orientation of the blastocyst at the nidation. A larger trial is now required, analyzing the placental features from IVF pregnancies in relation to the etiology of infertility.

Adult↗
PubMed2000

Cell culture of biopsied endometriomas after danazol/hormonal therapy: a study of growth features and fertility effects.

The growth features of cells from endometriomas biopsied from patients who had been treated with Danazol or with hormones have not been studied in vitro. Danazol is a versatile drug and despite its recognised efficacy in controlling endometriosis, little is known about is cytotoxicity and mechanism of action. Culture of the biopsied endometriomas permitted qualitative cytotoxic assessments by way of comparison with cultured normal uterine endometrial cells treated in vitro with Danazol. The growth characteristics were studied in monolayer and collagen gel cultures. Cytopathology was characterised by light and electron microscopy. Since endometriosis is associated with infertility in women, data from in vitro fertilisation (IVF) were analysed with respect to treatment modalities as compared with cases suffering fallopian occlusion. Danazol reduced pregnancy chances. Two factors may be responsible: (a) altered follicle development resulting in poor oocyte quality (b) reduced nidation because of long-lasting endometrial cytotoxicity. The experimental findings reported here support the latter explanation. Consequently, Danazol therapy should be conditional; patients wishing to achieve pregnancy should preferably receive hormonal therapy.

Cells, Cultured↗